The present invention relates to a process for calculating a new indice of arterial stiffness and/or a stroke volume, and to a device implementing this process.
Typically, a process or device according to the invention can be used for monitoring the stroke volume. In this case, the process or device according to the invention can be used in a medical or surgical Intensive Care Unit (ICU) and in an anesthesia unit, wherein such monitoring can be very useful.
Key Words: arterial stiffness, pulse pressure, hypertension, left ventricle, afterload, heart rate, cardiovascular risk factors, stroke volume
A growing number of clinical and epidemiological studies use aortic pulse contour analysis to document the role of increased pulsatile load and arterial stiffness throughout aging in subjects exposed to cardiovascular risk factors and in patients with various cardiovascular diseases [1-6]. Aortic pulse wave may be obtained from invasive catheterization or estimated from noninvasive techniques (eg, applanation tonometry).
Total arterial stiffness plays a contributory role throughout aging and in numerous cardiovascular diseases, including hypertension. Aortic stiffening is responsible for an increased characteristic impedance (ie, the impedance to the left ventricular pulsatile flow), thus increasing the forward pressure-wave amplitude that contributes to pulse pressure elevation. Aortic stiffening also increases pulse wave velocity, and this results in anticipated and enhanced wave reflections, further augmenting central pulse pressure. Unfortunately, there is no simple estimate of characteristic impedance. Furthermore, recent guidelines have reviewed the limitations of diastolic pulse contour analysis to estimate arterial stiffness.
The goal of the invention is to present a process and device for providing new and simple indices quantifying pulsatile load and/or arterial stiffness in humans, and/or for providing new and simple calculation of a stroke volume.